Washington state’s Building Code Council mandates heat pumps in all new residential construction

The Washington State Building Code Council has voted to require heat pumps for all new residential construction starting in July 2023.

The new mandate has drawn criticism over concerns that it will add costs to housing construction, especially given current supply chain challenges for heat pumps.

An official with the Building Industry Association of Washington said the measure was a “de facto ban on natural gas” because it would mean that bringing in gas lines for cooking, backup heating, and decorative fireplaces would be cost prohibitive.

The code also applies to system upgrades, the official said. Homeowners that would want to upgrade the output of their gas furnaces would have to install a heat pump instead.

One Washington legislator said the mandate would mean higher up-front costs that make housing less affordable, increased potential for brownouts and blackouts due to grid-capacity constraints, and the prospect of higher energy bills.